4/20 is like smoke -- it’s elusive, mysterious and ceremonial. The story of exactly how the exalted stoner holiday blazed into existence is the stuff of skunky legend.

Whether late Grateful Dead frontman Jerry Garcia invented it, or whether it’s meant to commemorate Bob Marley’s birthday, there’s no doubt that April 20 is the day that pot smokers of the world unite to toke up and party.

We do know one thing about this latest 4/20: partakers rolled out another kind of green in celebration -- greenbacks, and a lot of them. Total U.S. cannabis retail sales on the festive occasion exceeded $37.5 million, marking an almost 30 percent spike in retail transactions since last year’s 4/20 bonanza. So says a comprehensive report freshly baked by MJ Freeway, a global cannabis business seed-to-sale tracking software provider.

The Denver, Colo.-based startup, launched in 2010 by a team of veteran software and IT professionals, culled cannabis retail sales figures via data-driven analysis of what it claims to be 40 percent of the American cannabis market.

With more states allowing the recreational use of marijuana, legal retail sales of cannabis are estimated to skyrocket to $6.7 billion in sales this year alone. Last year, retail sales of the green stuff cha-chinged at approximately $5.7 billion in all. Clearly, the budding marijuana industry is on fire and not burning out any time soon.

"As the leading provider of cannabis software solutions, MJ Freeway has the largest and most representative retail data in the cannabis industry,” says Jessica Billingsley, MJ Freeway's chief operating officer, in a statement accompanying the report. “We have an unmatched vantage point from which to view trends and changes in the industry. This data is a powerful tool for understanding real-time cannabis industry changes and for predicting future trends.”

Doug Francis, CEO of Weedmaps, a popular online community for medical marijuana patients, says the spike in 4/20 cannabis retail sales mirrors the mainstreaming of legal cannabis on the whole. "Citizens are starting to come out of the green closet and seek information about the types of products available," he told Entrepreneur today. "Patients and consumers are more informed and savvier than ever about the wide variety of products available at dispensaries across the country. We anticipate strong continued growth across the entire sector as more states come online."

Here are some more April 20, 2016, cannabis sales numbers to toke on, also care of MJ Freeway’s number-crunching:

Individual legally-licensed cannabis retail locations -- medical and recreational and dispensaries and delivery services -- sold on average $10,822 in retail sales on April 20, $6,208 on April 19 and $5,442 on April 18.

While buyer traffic increased, buyers spent on average $20 less per transaction on April 20, 2016, vs. April 20, 2015.

The state with the largest dollar amount sold on April 20, 2016, was California.

The state with the total highest average sales per day per retail licensed location for April 20, 2016, was -- not surprisingly -- Colorado.